1. Technical Field
This disclosure relates to a sheet cutting device and an image forming apparatus including the sheet cutting device, and more specifically to a sheet cutting device to cut a rolled sheet to a desired length and an image forming apparatus including the sheet cutting device.
2. Description of the Related Art
Image forming apparatuses are used as printers, facsimile machines, copiers, plotters, or multi-functional devices having two or more of the foregoing capabilities. As a conventional type of image forming apparatus, an image forming apparatus is known that feeds a long-size rolled sheet (hereinafter, rolled sheet) in a certain feed direction (hereinafter, sheet feed direction) to form an image on the rolled sheet. The image forming apparatus typically has a sheet cutting device to cut the rolled sheet to a desired length.
As the sheet cutting device, for example, JP2009-214200-A proposes a sheet cutting device that has a cutter assembly and guide rails. The cutter assembly has a cutter holder accommodating a cutter and a slider serving as a moving unit integrally provided with the cutter holder. The guide rails guide the slider slidably in the width direction of the rolled sheet. The cutter assembly cuts the rolled sheet while moving to one end in the width direction of the rolled sheet, and after cutting the sheet, the cutter assembly is returned to the other end in the width direction to prepare for the next sheet cutting. On the slider is mounted a drawing belt wound around a pulley of a cutter motor. Thus, a rotation driving force of the cutter motor is transmitted to the slider via the drawing belt to move the slider in the width direction of the rolled sheet.
In the sheet cutting device, after the cutting operation of the cutter ends, the cutter assembly is tilted toward the downstream side in the sheet feed direction around a guide member. As a result, the forward path along which the cutter moves to cut the rolled sheet differs from the backward path along which the cutter moves to retract after cutting the sheet. Such a configuration can prevent the cutter from contacting a subsequent one of divided sheets on the backward path, thus preventing a cut jam or other failure.
However, in the sheet cutting device, the cutter assembly is tilted between the forward path and the backward path, thus causing the drawing belt to twist between the slider and the pulley. As a result, each time the sheet cutting operation is performed, the drawing belt is repeatedly twisted, thus adversely affecting durability of the drawing belt.
Hence, for example, it is conceivable to provide the slider independent of the cutter holder and tilt only the cutter holder relative to the slider. Alternatively, it is conceivable to retract the cutter holder from a sheet feed path in a thickness direction of the sheet relative to the slider. Such configurations can prevent twist of the drawing belt.
However, such configurations have another challenge of a position at which the cutter holder is connected to the slider, in order to allow stable movement of the cutter holder. In other words, if the position at which the cutter holder is connected to the slider is placed upstream from a position at which the cutter is accommodated in the cutter holder, in a cutting direction (i.e., a direction in which the cutter holder moves to cut the sheet), the cutter holder rattles and cannot stably move. As a result, during cutting operation, sheet cockling or jam may occur, thus hampering stable sheet cutting operation.